1. Field of the Invention
The present invention relates generally to rotating machines and more specifically to designs for retaining bearings in rotating machines.
2. Description of the Related Art
In rotating machines, a rotating member affixed to a shaft is frequently supported on at least one end by a bearing. The bearing is affixed within a bearing pocket in a housing of the machine.
In some cases, assembly of the machine can be facilitated if the rotor is assembled within the two halves of the housing prior to incorporation of the aforementioned bearing. When the machine is so assembled, an end of the shaft protrudes into the bearing pocket. A bearing is then simultaneously pressed both into the pocket (the outer race of the bearing) and onto the shaft (the inner race of the bearing). However, some manner must be provided to allow axial movement of the bearing into the bearing pocket for this assembly sequence to be successful.
One way to allow axial movement of the bearing is to use a bearing having an "expansion compensation" band, an elastomeric band, about the outer race. Such a bearing, however, is expensive and is available from a relatively limited number of suppliers. Another way to allow axial movement is to heat the housing to expand the bearing pocket immediately prior to insertion of the bearing. However, when the housing cools and the bearing pocket contracts, the resulting stresses may pre-load the bearing. This can shorten bearing life. Thus, an improved design which allows for axial movement of the bearing during assembly will facilitate the use of cost-effective standard bearings without the stresses introduced through heating the housing of the machine.
Also, protecting the bearing from external contaminants is important in assuring long bearing life. In a presently-known design, a stamped metal dust cover is pressed into the housing to cover the exterior of the bearing. However, dust covers installed in that manner may not always be adequately secure. Thus, a design which cost-effectively and robustly provides for protection of the bearing will be advantageous.